Hillary Clinton speaks at a ceremony in Beijing on May 3, 2012, during a trip to China while she was secretary of state. (REUTERS/Shannon Stapleton)

A day before the Iowa caucuses get underway, amid a stream of posts about the state, Hillary Clinton on Sunday blasted Chinese authorities for reportedly shuttering a women's legal clinic in Beijing.

In a message to her 5.26 million Twitter followers, Clinton referenced her keynote speech at the 1995 United Nations Fourth World Conference on Women in Beijing — "women's rights are human rights" — and expressed solidarity with the center's founder, Guo Jianmei. "I stand with Guo," she wrote, signing the tweet "-H."

The message came just months after the candidate made headlines for using social media to criticize China's president, Xi Jinping, ahead of his speech at a U.N. women's summit. In that tweet, also signed "-H," she criticized Xi for speaking at a women's conference in New York while jailing feminists at home. "Shameless," she wrote.

That Clinton again took to her account to call out Chinese authorities is telling, a reminder of the candidate's long and complicated engagement with the country and her willingness to talk tough, particularly on women's rights.

Clinton delivered the keynote speech at the 1995 conference. In what CNN last year called her "most iconic moment," the then-first lady stood at a podium in Beijing and, without naming China, lambasted governments that curtail women's rights by denying them the right to plan their families or forcing them to have abortions.

For Chinese authorities, it was an outrage; her remarks were censored and state media went on the offensive, questioning how the United States treated its own women. Stateside, it was a different story: An editorial in the New York Times called her showing "unflinching," venturing that it "may have been her finest moment in public life."

Guo Jianmei's legal aid group was founded that same year, and Clinton visited the organization during her visit to China in 1998.

On June 29, 1998, first lady Clinton and then-Secretary of State Madeleine Albright visited Guo and her team at their Beijing office. The organization was taking on tough cases — a 16-year-old raped by a high school principal, women fined under the one-child policy — and seeing results. Clinton called their efforts "ground-breaking," according to a report by the New York Times.

In the years since, Guo has continued to advocate for women. For 15 years, the center was housed at Peking University. In 2010, it was forced to close, though Guo subsequently reopened the center, now called the Beijing Zhongze Women’s Legal Counseling and Service Center, in a new location.

It is not clear why the center is being shut down again; however, its closure comes amid an unprecedented crackdown on civil and human rights lawyers and their associates and as the government hammers out a new law to control domestic and foreign civic groups. (Reached by phone, Guo declined to comment on the case.)

Clinton's pointed Twitter message — "I stand with Guo" — will not be popular in Beijing, as she well knows.

When she called Xi's U.N. speech "shameless," state media hit back, with the Global Times, a newspaper known for its nationalist rhetoric, denouncing the comment as "more than reminiscent of the demagogue Donald Trump."

"Despite her political acumen as former secretary of state and senator, she is using the language of Trump to cast herself in the role of a rabble-rouser," read the unsigned editorial.

Clinton's reply to that charge seemed to predict Sunday's post: "If China believes defending women's rights is 'rabble rousing,'" she said in a statement, "then they can expect much more of it from me."